/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Public/OnlineSubsystemUtils.h
Bind a notification delegate when any subsystem external UI is opened/closedNOTEthere is only meant to be one delegate needed for this, game code should bind manually
void SetEngineExternalUIBinding ( const [FOnExternalUIChangeDelegate](API\Plugins\OnlineSubsystem\Interfaces\FOnExternalUIChangeDelegate) & OnExternalUIChangeDelegate )